Gas supply method

Abstract

The present invention provides a gas supply method for supplying hydrogen gas and carbon dioxide gas to an object that utilizes at least one of these gases. [Solution] A gas supply method using a gas generator 20 that generates hydrogen gas and carbon dioxide gas by introducing liquid formic acid includes a transport step S1 of transporting formic acid in liquid form to the gas generator 20, and a gas supply step S2 of supplying at least one of the hydrogen gas and carbon dioxide gas generated by the gas generator 20 to a supply target 30 located near the gas generator 20.

Description

Technical Field

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[0001] The present invention relates to a gas supply method.

Background Art

[0002] Hydrogen gas and carbon dioxide gas are industrially used. For example, hydrogen gas is used as fuel for fuel cells. Also, carbon dioxide gas is used to promote the growth of crops and algae.

[0003] Also, a technique for decomposing formic acid to obtain hydrogen gas and carbon dioxide gas is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0009] Specifically, the invention for achieving the above objective is a gas supply method using a gas generator that generates hydrogen gas and carbon dioxide gas by introducing liquid formic acid, the gas supply method comprising the steps of: transporting the formic acid in a liquid state to the gas generator; and supplying at least one of the hydrogen gas and carbon dioxide gas generated by the gas generator to an object provided near the gas generator. [Effects of the Invention]

[0010] According to the present invention, a gas supply method can be provided for supplying hydrogen gas and carbon dioxide gas to an object that utilizes at least one of these gases. [Brief explanation of the drawing]

[0011] [Figure 1] This is a flowchart showing each step in the gas supply method. [Figure 2] This is a schematic diagram showing the outline of a facility that uses a gas supply method. [Figure 3] This is a schematic diagram showing an overview of the transportation process S1. [Figure 4] This is a schematic diagram showing an overview of the gas supply process S2. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below are subject to various technically preferred limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0013] <Overview of Gas Supply Method> Figure 1 is a flowchart showing each step of the gas supply method according to an embodiment of the present invention. Figure 2 shows an overview of a facility using the gas supply method according to an embodiment of the present invention. The gas supply method in this embodiment consists of a transport step S1 in which liquid formic acid is transported from the formic acid manufacturing plant 10 to the gas generator 20, and a gas supply step S2 in which hydrogen gas and carbon dioxide gas are generated by the gas generator 20 and these gases are supplied to the supply target 30. Details of each step will be described later.

[0014] The formic acid production plant 10 is a plant that produces liquid formic acid (CH2O2). The formic acid production plant 10 produces formic acid by known methods. Examples of methods for producing formic acid include a method using hydrogen (H2), carbon dioxide (CO2), and a catalyst; a method for producing formic acid as a byproduct when producing acetic acid (C2H4O2); and a method for producing formic acid using biogas, which is a mixed gas of methane (CH4) and carbon dioxide, and a catalyst. The formic acid production plant 10 has a formic acid production apparatus 11 for producing formic acid, a concentration apparatus 12 for concentrating liquid formic acid to increase its concentration, and a storage tank 13 for storing liquid formic acid. However, the formic acid production plant 10 does not necessarily have a storage tank 13.

[0015] The formic acid production apparatus 11, the concentration apparatus 12, and the storage tank 13 are connected by piping. The formic acid produced in the formic acid production apparatus 11 flows through the piping to the concentration apparatus 12. The formic acid that flows into the concentration apparatus 12 is concentrated to become high-concentration formic acid. This high-concentration formic acid then flows through the piping to the storage tank 13 and is stored in the storage tank 13 in liquid form.

[0016] The gas generator 20 is a device that generates hydrogen gas and carbon dioxide gas from liquid formic acid. The gas generator 20 is provided at a location separate from the formic acid manufacturing plant 10 (for example, a location more than 1 kilometer away from the formic acid manufacturing plant 10). The gas generator 20 generates hydrogen gas and carbon dioxide gas from formic acid by a known method. Examples of the method for generating gas include a method using a catalyst and a high-pressure hydrogen supply system disclosed in JP-A-2023-27674. Near the gas generator 20, a temporary storage tank 21, a separation device 22, and a purification device 23 are provided.

[0017] The temporary storage tank 21 temporarily stores the liquid formic acid transported from the formic acid manufacturing plant 10. The temporary storage tank 21 is connected to the gas generator 20 by piping. Note that the temporary storage tank 21 may not be provided, and the transported liquid formic acid may be directly supplied to the gas generator 20.

[0018] The separation device 22 separates the mixed gas of hydrogen gas and carbon dioxide gas generated by the gas generator 20 into hydrogen gas and carbon dioxide gas. Examples of the separation device 22 include a device using a separation membrane, a device performing distillation, and the like. The separation device 22 is connected to the gas generator 20 by piping.

[0019] The purification device 23 removes impurities (carbon dioxide, carbon monoxide, methane, moisture, etc.) from the hydrogen gas. The purification device 23 removes impurities from the hydrogen gas and purifies high-purity hydrogen. Examples of the purification device 23 include a device that removes impurities using a catalyst, a device using a permeation membrane that allows only hydrogen gas to permeate, and the like. The purification device 23 is connected to the separation device 22 by piping. Note that when the supply target 30 uses low-purity hydrogen (that is, does not require high-purity hydrogen), the purification device 23 may not be provided. In that case, the hydrogen gas is directly supplied from the separation device 22 to the supply target 30.

[0020] The supply target 30 is a facility to which hydrogen gas and carbon dioxide gas generated by the gas generator 20 are supplied. The supply target 30 is provided near the gas generator 20 and is connected to the separation device 22 and the purification device 23 by pipes. The supply target 30 is a facility that uses hydrogen gas and carbon dioxide gas, a facility that uses either hydrogen gas or carbon dioxide gas, or a composite facility provided with a plurality of these facilities. In the present embodiment, the supply target 30 includes a hydrogen gas utilization facility 31, a carbon dioxide gas utilization facility 32, a hydrogen gas tank 33, and a carbon dioxide gas tank 34. Note that the supply target 30 may be configured not to include the hydrogen gas tank 33 and the carbon dioxide gas tank 34.

[0021] The hydrogen gas utilization facility 31 is a facility that uses the hydrogen gas generated by the gas generator 20. The hydrogen gas utilization facility 31 is provided near the gas generator 20 and is connected to the purification device 23 by a pipe. In the hydrogen gas utilization facility 31, those that use hydrogen gas, such as a filling device for filling hydrogen into a vehicle and a fuel cell, are arranged. The hydrogen gas utilization facility 31 includes, for example, a hydrogen station, a power plant, and the like.

[0022] The carbon dioxide gas utilization facility 32 is a facility that uses the carbon dioxide gas generated by the gas generator 20. The carbon dioxide gas utilization facility 32 is provided near the gas generator 20 and is connected to the separation device 22 by a pipe. In the carbon dioxide gas utilization facility 32, those that use carbon dioxide gas, such as plants and devices, are arranged. The carbon dioxide gas utilization facility 32 includes, for example, greenhouse facilities for plants, cultivation facilities for algae, dry ice manufacturing factories, and the like.

[0023] The hydrogen gas tank 33 is a tank for temporarily storing hydrogen gas generated by the gas generator 20. The hydrogen gas tank 33 is located between the purification unit 23 and the hydrogen gas utilization equipment 31 in the hydrogen gas flow path supplied from the gas generator 20 to the hydrogen gas utilization equipment 31. A valve is also provided in the hydrogen gas flow path connecting the hydrogen gas tank 33 and the hydrogen gas utilization equipment 31. The amount of hydrogen gas supplied from the hydrogen gas tank 33 to the hydrogen gas utilization equipment 31 is adjusted by opening and closing the valve.

[0024] The carbon dioxide gas tank 34 is a tank that temporarily stores the carbon dioxide gas generated by the gas generator 20. The carbon dioxide gas tank 34 is installed between the separation device 22 and the carbon dioxide gas utilization equipment 32 in the flow path of carbon dioxide gas supplied from the gas generator 20 to the carbon dioxide gas utilization equipment 32. A valve is also provided in the flow path of carbon dioxide gas connecting the carbon dioxide gas tank 34 and the carbon dioxide gas utilization equipment 32. The amount of carbon dioxide gas supplied from the carbon dioxide gas tank 34 to the carbon dioxide gas utilization equipment 32 is adjusted by opening and closing the valve.

[0025] <Details of each step> (Transportation process S1) The transport process S1 is the process of transporting liquid formic acid. Figure 3 shows an overview of the transport process S1. First, the formic acid production apparatus 11 of the formic acid production plant 10 produces formic acid. Next, the concentration apparatus 12 concentrates the formic acid produced by the formic acid production apparatus 11 to produce high-concentration formic acid. Next, the storage tank 13 stores the high-concentration formic acid in liquid form. Next, the transport means transports the formic acid stored in the storage tank 13 in liquid form to the gas generator 20, which is located in a different location from the formic acid production plant 10. Here, the transport means can be a vehicle, a railway, a ship, etc. Finally, the temporary storage tank 21 stores the formic acid transported by the transport means in liquid form.

[0026] (Gas supply process S2) The gas supply process S2 is a process of supplying at least one of hydrogen gas and carbon dioxide gas to the target. Figure 4 shows an overview of the gas supply process S2. First, the gas generator 20 is fed formic acid stored in the temporary storage tank 21. Next, the gas generator 20 generates hydrogen gas and carbon dioxide gas. Next, the gas generator 20 supplies the hydrogen gas and carbon dioxide gas to the separation unit 22.

[0027] The separation unit 22 separates the mixed gas of hydrogen gas and carbon dioxide gas generated by the gas generator 20 into hydrogen gas and carbon dioxide gas. Next, the separation unit 22 supplies the hydrogen gas to the purification unit 23 and the carbon dioxide gas to the carbon dioxide gas tank 34 of the target supply 30.

[0028] The purification unit 23 removes impurities from the hydrogen gas and purifies it into high-purity hydrogen gas. Next, the purification unit 23 supplies the hydrogen gas to the hydrogen gas tank 33 of the target 30.

[0029] The hydrogen gas tank 33 temporarily stores the supplied hydrogen gas. The hydrogen gas utilization equipment 31 is then supplied with the hydrogen gas stored in the hydrogen gas tank 33. The amount of hydrogen gas supplied from the hydrogen gas tank 33 to the hydrogen gas utilization equipment 31 may be adjusted according to the amount of hydrogen gas used by the hydrogen gas utilization equipment 31.

[0030] The carbon dioxide gas tank 34 temporarily stores the supplied carbon dioxide gas. The carbon dioxide gas utilization equipment 32 is then supplied with the carbon dioxide gas stored in the carbon dioxide gas tank 34. The amount of carbon dioxide gas supplied from the carbon dioxide gas tank 34 to the carbon dioxide gas utilization equipment 32 may be adjusted according to the amount of carbon dioxide gas used by the carbon dioxide gas utilization equipment 32.

[0031] If the supply target 30 does not have a hydrogen gas tank 33 and a carbon dioxide gas tank 34, the separation unit 22 will supply carbon dioxide gas to the carbon dioxide gas utilization equipment 32. In addition, the purification unit 23 will supply hydrogen gas to the hydrogen gas utilization equipment 31.

[0032] <Effects> The gas supply method in this embodiment is a gas supply method using a gas generator 20 that generates hydrogen gas and carbon dioxide gas by introducing liquid formic acid, and includes a transport step S1 of transporting formic acid in liquid form to the gas generator 20, and a gas supply step S2 of supplying at least one of the hydrogen gas and carbon dioxide gas generated by the gas generator 20 to a supply target 30 provided near the gas generator 20.

[0033] Since formic acid is a liquid substance at room temperature, it is easier to transport than a gas. According to the method described above, formic acid is transported in liquid form to the gas generator 20, and hydrogen gas and carbon dioxide gas are generated by introducing the liquid formic acid into the gas generator 20. At least one of the hydrogen gas and carbon dioxide gas generated in the gas generator 20 is then supplied to the target 30. In other words, a gas supply method is provided that supplies at least one of hydrogen gas and carbon dioxide gas to a target that utilizes these gases.

[0034] Furthermore, since the above method transports formic acid in liquid form, the transport tank does not need to be a pressure-resistant vessel capable of withstanding high pressure, like a gas tank. Therefore, it can be transported more easily and at a lower cost than transporting hydrogen gas or carbon dioxide gas.

[0035] Furthermore, if the supply target 30 utilizes both hydrogen gas and carbon dioxide gas, these gases generated by the gas generator 20 can be used without being discarded. [Explanation of Symbols]

[0036] 20...Gas generator 30…Target of supply

Claims

[Claim 1] A gas supply method using a gas generator that generates hydrogen gas and carbon dioxide gas by introducing liquid formic acid, A step of transporting the formic acid in liquid form to the gas generator, A step of supplying at least one of the hydrogen gas and carbon dioxide gas generated by the gas generator to an object located near the gas generator, A method for supplying gas, including [a specific gas].

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